The Walking Stick(1970)

A young woman's highly ordered and structured life is turned upside-down when she meets a handsome stranger at a party. Friendship soon develops into romance and for the first time in her life she is truly happy. This happiness is short lived, however, as little by little she discovers her partner has been lying to her about his past. It is soon revealed that he and his friends have been planning to rob the auction house that she works for and they require her inside knowledge in order to pull off the crime.